相关疑难解决方法(0)

我不明白变量行后的逗号是什么,意思是:http://matplotlib.org/examples/animation/simple_anim.html

line, = ax.plot(x, np.sin(x))

如果我删除逗号和变量"line",变为变量"line",则程序被破坏.上面给出的url的完整代码:

import numpy as np
import matplotlib.pyplot as plt
import matplotlib.animation as animation

fig = plt.figure()
ax = fig.add_subplot(111)

x = np.arange(0, 2*np.pi, 0.01)        # x-array
line, = ax.plot(x, np.sin(x))

def animate(i):
    line.set_ydata(np.sin(x+i/10.0))  # update the data
    return line,

#Init only required for blitting to give a clean slate.
def init():
    line.set_ydata(np.ma.array(x, mask=True))
    return line,

ani = animation.FuncAnimation(fig, animate, np.arange(1, 200), init_func=init,
    interval=25, blit=True)
plt.show()

根据http://docs.python.org/3/tutorial/datastructures.html#tuples-and-sequences逗号后变量似乎与仅包含一个项目的元组有关.